cvs commit: src/sys/dev/usb ehci.c ohci.c

Sam Leffler sam at freebsd.org
Wed Apr 23 20:43:59 UTC 2008


Marius Strobl wrote:
> On Sat, Apr 12, 2008 at 09:33:58PM +0200, Marius Strobl wrote:
>   
>> On Thu, Mar 20, 2008 at 04:19:26PM +0000, Sam Leffler wrote:
>>     
>>> sam         2008-03-20 16:19:25 UTC
>>>
>>>   FreeBSD src repository
>>>
>>>   Modified files:
>>>     sys/dev/usb          ehci.c ohci.c 
>>>   Log:
>>>   Workaround design botch in usb: blindly mixing bus_dma with PIO does not
>>>   work on architectures with a write-back cache as the PIO writes end up
>>>   in the cache which the sync(BUS_DMASYNC_POSTREAD) in usb_transfer_complete
>>>   then discards; compensate in the xfer methods that do PIO by pushing the
>>>   writes out of the cache before usb_transfer_complete is called.
>>>   
>>>   This fixes USB on xscale and likely other places.
>>>   
>>>   Sponsored by:   hobnob
>>>   Reviewed by:    cognet, imp
>>>   MFC after:      1 month
>>>   
>>>   Revision  Changes    Path
>>>   1.62      +16 -0     src/sys/dev/usb/ehci.c
>>>   1.171     +16 -0     src/sys/dev/usb/ohci.c
>>>       
>> This causes a crash during boot on sparc64. Looks like map is still
>> NULL at that point.
>>
>>     
>
> Are you ok with the change below or would that also prevent
> your kludge from taking effect?
>
> Marius
>
> Index: ehci.c
> ===================================================================
> RCS file: /usr/data/bsd/cvs/fbsd/src/sys/dev/usb/ehci.c,v
> retrieving revision 1.62
> diff -u -r1.62 ehci.c
> --- ehci.c	20 Mar 2008 16:19:25 -0000	1.62
> +++ ehci.c	23 Apr 2008 20:23:58 -0000
> @@ -664,6 +664,8 @@
>  	usbd_pipe_handle pipe = xfer->pipe;
>  	bus_dma_tag_t tag = pipe->device->bus->buffer_dmatag;
>  	struct usb_dma_mapping *dmap = &xfer->dmamap;
> +	if (dmap->map == NULL)
> +		return;
>  	bus_dmamap_sync(tag, dmap->map, BUS_DMASYNC_PREWRITE);
>  }
>  
> Index: ohci.c
> ===================================================================
> RCS file: /usr/data/bsd/cvs/fbsd/src/sys/dev/usb/ohci.c,v
> retrieving revision 1.171
> diff -u -r1.171 ohci.c
> --- ohci.c	20 Mar 2008 16:19:25 -0000	1.171
> +++ ohci.c	21 Apr 2008 19:13:54 -0000
> @@ -1571,6 +1571,8 @@
>  	usbd_pipe_handle pipe = xfer->pipe;
>  	bus_dma_tag_t tag = pipe->device->bus->buffer_dmatag;
>  	struct usb_dma_mapping *dmap = &xfer->dmamap;
> +	if (dmap->map == NULL)
> +		return;
>  	bus_dmamap_sync(tag, dmap->map, BUS_DMASYNC_PREWRITE);
>  }
>  
>
>
>   
You have not identified why you don't have a dma map.  I don't have a 
way to diagnose your problem and so far as I know no other platform had 
an issue w/ the change.  I suggest you figure out why your map is not 
setup instead of adding a hack.

    Sam



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